About this Abstract |
| Meeting |
TMS Specialty Congress 2026
|
| Symposium
|
4th World Congress on High Entropy Alloys (HEA 2026)
|
| Presentation Title |
A Pinch of Oxygen: A Game Changer for Microstructure and Strength in Refractory High-Entropy Alloys |
| Author(s) |
Mariano Casas-Luna, František Lukáč, Eduard Bastl, Michal Knapek, Josef Stráskŭ |
| On-Site Speaker (Planned) |
Mariano Casas-Luna |
| Abstract Scope |
One approach to improving the properties of Complex Concentrated Alloys (CCAs) involves adding interstitial elements such as oxygen, which influence phase stability and mechanical behavior. However, the impact of interstitial oxygen remains largely unexplored across the vast compositional space of CCAs.
This study investigates two refractory CCAs within the AlCrNbTiZr and AlMoNbTiZr systems, designed to be low-density and single-phase using the CALPHAD method to ensure a body-centered cubic (bcc) structure. Interstitial oxygen was introduced by adding titanium oxide, targeting up to 3.0 at.% (<1.0 wt.%) oxygen. The alloys were fabricated by spark plasma sintering and arc-melting techniques. Phase stability and hardness were evaluated after annealing at 1250°C for 48 hours and quenching. Microstructural observation provides insight into the role of oxygen in atomic segregation and diffusion of high-melting-point constituents within the bcc solid solution and in the resulting hardness increase, offering guidance for developing interstitial-oxygen HEAs with improved mechanical properties. |
| Proceedings Inclusion? |
Undecided |